The present invention relates to a method and apparatus for transporting and sorting flowers or other stem-shaped or elongate products, with a conveyor provided with arm-fork units which are moved along a transport path in a substantially horizontal plane.
In particular, such a method comprises:
taking over a substantially vertically hanging flower from a take-over position with a fork at the end of the arm-fork unit remote from the conveyor,
transporting the flowers, along the transport path and with the arm-fork unit in a transport position, to an apparatus for bunching the transported flowers with generally several bunching stations, the transport taking place in said plane along at least one detector for detecting at least one flower characteristic, whereby detection signals are obtained,
processing the detection signals in a processing unit into corresponding selection signals,
controlling the arm-fork units with the selection signals for delivering the flower to a corresponding selected bunching station, whereby the arm-fork unit is brought in the horizontal plane to a delivery position by moving the arm-fork unit, during movement along the transport path, over some distance away from the conveyor out of the transport position to subsequently deliver the flower from the fork to the selected bunching station.
Such an apparatus comprises, in particular:
detection elements for detecting at least one flower-characteristic during the transport of the flowers to an apparatus for bunching the transported flowers with generally several bunching stations, whereby detection signals are obtained,
a processing unit for processing the detection signals into corresponding selection signals,
control elements for bringing, in response to the selection signals, the arm-fork units into a delivery position for delivering the flower at a delivery position to a corresponding selected bunching station, the arm-fork unit being movable in said horizontal plane from a transport position over some distance away from the conveyor to the delivery position.
Apparatuses of that type are known from, for instance, U.S. Pat. Nos. 5,157,899 and 3,659,709. Both documents show a series of arm-fork units, mounted on a chain of an endless conveyor which circulates in a horizontal plane. The units are so constructed that in that plane at defined positions flowers can be hung into forks and at other well-defined positions these flowers can be delivered and can be gathered into bunches to be bundled. According to U.S. Pat. No. 5,157,899 the forks are located in line with an arm extendable in a direction perpendicular to the conveyor. In U.S. Pat. No. 3,659,709, forks with arms in the form of a parallelogram construction are pivoted away from and back to the chain of the conveyor, while the forks, as in U.S. Pat. No. 5,157,899, maintain a position perpendicular to the chain.
In both apparatuses, the flexibility is lacking in taking over and delivering fragile products such as flowers, for instance roses, because the fork, in particular the direction of the fork pins, is always fixed perpendicular to the transport direction.
U.S. Pat. No. 5,157,899 exhibits the disadvantage that for large flowers the mutual distance between the arm-fork units in many cases proves to be too small, so that flowers aet entangled with each other.
U.S. Pat. No. 3,659,709, by contrast, has the disadvantage that although sufficient space has been created to separate the flowers from each other during transport, the use of a parallelogram construction, which defines both the intermediate distance along the conveyor as well as the perpendicular distance from the conveyor, renders this intermediate distance very large, so that the number of products that can be transported per unit length is limited considerably.
To remedy these shortcomings, in accordance with the invention, the method according to the prior art represented above is characterized in that for assuming the delivery position the fork is rotated relative to the transport position to a delivery position.
The apparatus according to the invention is characterized in that the arm-fork units, at the remote ends, have rotation elements to rotate the fork relative to the transport position to a rotation end angle which corresponds with the delivery position.
This method and apparatus not only have the advantage that they are space-saving, but also that the number of rotary parts of the arm-fork unit is limited. A further considerable advantage is achieved through the basically adjustable rotation and the associated rotation end angle. These measures enable a flexible positioning of supply and discharge devices.
In a further elaboration, the method is characterized in that the fork is rotated in the horizontal plane, while the delivery position of the fork is in line with the arm, perpendicular to the transport direction, and more in particular, the fork is rotated through an angle of at most xe2x88x92180xc2x0 relative to the transport direction.
A next embodiment of the method according to the present invention is characterized in that for taking over the flower the fork is rotated relative to the transport position to a take-over position, more in particular, that the fork is rotated in the horizontal plane, while in a preferred embodiment the fork is rotated through an angle of at most xe2x88x92180xc2x0 relative to the transport direction, and in the horizontal plane the fork is brought to the take-over position while the arm-fork unit, during movement along the transport path, is moved over some distance away from the conveyor to subsequently take over the flower from the take-over position.
In a still further embodiment, the method according to the present invention is characterized in that the flowers are embraced between substantially the take-over position and the delivery position.
The great advantage of this is that at take-over the flowers are immediately embraced without getting entangled with flowers hanging next to them, and moreover that swerving out and possible entanglement during transport are prevented entirely.
According to a further embodiment, the apparatus according to the present invention is characterized in that the rotation elements perform a rotation to the rotation end angle in the horizontal plane, whereby the fork, against a restraining force, is brought in line with the arm-fork unit, perpendicular to the transport direction.
In a further exemplary embodiment, the apparatus according to the present invention is characterized in that the rotation elements in the remote end of the arm-fork unit comprise a fork with shaft-hole assembly, a rotation limiting system for limiting the rotation as far as the end angle, as well as a non-elastic drive belt, while the arm-fork unit is mounted so as to be slidable transversely to the conveyor, on a sliding block mounted on the conveyor and moving along therewith, with a vertical downwardly directed rod in the proximal end of the arm-fork unit, and a guide roller on the sliding block on one side of the unit, while the drive belt is connected by one end thereof with the lower end of the rod and extends over the guide roller and then under engaging friction around the fork shaft on the other side of the unit to the proximal end of the unit and is elastically connected therewith, more particularly, the drive belt is connected with a draw spring to the proximal end of the arm-fork unit, while as a further feature, the control elements comprise
a curve plate, fixedly arranged along the conveyor, and on each arm-fork unit a curve follower, which, as soon as it butts against the curve plate upon advancement of the conveyor along the transport path, follows the curve plate, and gradually moves the arm-fork unit from its transport position away from the conveyor, and while in a further suitable manner the drive belt is connected with the lower end of the rod by means of a slide bearing, while a compression spring extends between the slide bearing and the arm-fork unit, while the compression spring is only compressed between the reaching of the rotation end angle and the delivery position, and the compression spring relaxes upon sliding back of the arm-fork unit following a step-shaped recess in the curve plate to a parking position, whereafter the arm-fork unit is gradually returned along a return sector to its transport position.
Such an apparatus with resilient drive prevents in a suitable manner a rigid positioning of the forks. Small deviations, for instance due to curved or stiff flower stems, can be accommodated in an advantageous manner.
In a further elaboration, the apparatus further comprises a monitoring element for monitoring the offer of new flowers to be taken over by the arm-fork unit, collected in a presenting element, and a second curve plate for bringing the arm-fork unit into a take-over position in response to a signal delivered by the monitoring element, while the flowers in a take-over position are taken over by the arm-fork unit from the presenting element, the presenting element being a fork, and more particularly the arm-fork units have a projection to lock the units in the delivery position with a catch connected with the conveyor.
The apparatus according to the invention is further characterized in that the apparatus further comprises clamping elements for embracing the flowers to be transported, between substantially the take-over position and the delivery position, and more particularly, that the clamping elements comprise two hinging fork pins, while the fork pins axe mounted in curve follower blocks for following a first clamping curve plate after taking over the flower and a second curve plate after delivering the flower.